The proposed study is designed to evaluate the relation between emotion and health status in persons living with HIV disease, with a special emphasis on positive emotion. Emotions are believed to relate to health via biological and behavioral pathways. This study will assess whether rates of positive and negative emotion relate to 1) health behaviors (smoking, alcohol/drug use, physical activity, diet, sexual risk, and medication adherence), 2) salivary cortisol, and 3) indicators of health status (CD4+ cell count, viral load, severity of HIV/AIDS related illnesses, general physical health, and general mental health) in persons with HIV disease. Cortisol and health behaviors will be tested as mediators of the relation between emotion and health status. A majority of research has focused on the effects of negative emotion, and studies have generally failed to adequately account for interaction effects between positive and negative emotion. The current study takes a unique approach in integrating the broaden and build theory of positive emotion with existing theory in order to develop hypotheses specific to positive emotion and health behaviors, cortisol, and health status. In accordance with the "undoing" effect described in the broaden and build theory, it is hypothesized that using hierarchical regression analysis, an interaction model integrating both positive and negative emotion will provide a more complete picture of the relation between emotion and health than models based on positive and negative emotion alone. Specifically, it is hypothesized that in addition to the independent relations of positive and negative emotion to cortisol, health behaviors, and health status, positive emotion will moderate negative emotion such that the relation between negative emotion and these measures will be significantly weaker in persons who report high rates of positive emotion compared to persons who report low rates of positive emotion. If this is the case, future interventions may benefit from targeting enhancement of positive emotion in addition to reduction of negative emotion. The burden of living with HIV disease remains significant despite dramatic improvements in medical care. This study represents early work in the process of developing future interventions aimed at improving emotional experience in order to improve health and well-being in persons living with HIV disease. PUBLIC HEALTH RELEVANCE: When effective, behavioral interventions can serve as supplements to standard medical care that may improve health status and reduce risk of future adverse health events without adding any additional burden of side effects from medication.